ON ITS EXTEKTOE. YOLCAXOES. 237 



district, born amidst basaltic and trachytic mountains, 

 these once familiar forms, when seen again in a strange 

 land, often seem, as it were, to greet him with a home- 

 like welcome. The forms of mountains are among the 

 most important of the elements which determine the 

 "physiognomy of nature;" they give to the aspect of 

 the region in which they are seen, according as they are 

 adorned with vegetation or soar aloft in desert naked- 

 ness, a cheerful, or a grave and majestic character. I 

 have very lately tried to place side by side in a separate 

 atlas a number of sketches, taken from drawings of my 

 own, of the Cordilleras of Quito and Mexico. As basalt 

 appears sometimes in cones rounded off at the summit, 

 sometimes as twin mountains placed close to each other 

 but of unequal height, sometimes as a long horizontal 

 ridge having two higher rounded summits at either 

 extremity ; so in the trachyte we distinguish pre- 

 eminently the majestic dome ( 321 ) of Chimborazo (21,422 

 feet), a form not to be confounded with that of the also 

 unopened, but more slender, " bell-shaped " mountains. 

 The conical form is seen in the greatest degree of per- 

 fection ( 322 ) in Cotopaxi (18,877 feet) ; and next to it in 

 Popocateptl ( 323 ) (17,726 feet), as seen from the beautiful 

 shores of the lake of Tezcuco, or from the top of the 

 ancient Mexican terraced pyramid of Cholula ; and 

 in the volcano ( 324 ) of Orizaba (17,374, or, according 

 to Ferrer, 17,879 feet). A strongly truncated cone- 

 shape ( 3 ' 5 ) is seen in the Nevado de Cayambe-Urcu 

 (19,365 feet) immediately under the equator, and also 

 in the volcano of Tolima (18,128 feet), as seen rising 

 from behind the primeval forest, from the foot of the 

 Paramo of Quindiu, near the little town of Ibague. ( 326 ) 



